One quintillion pennies. This many pennies, if laid out flat like a carpet, would cover the surface of the earth - twice. If you look hard, you can still see the Sears Tower and other buildings at lower right. Another way to see it is to realize that Mt. Everest (29,000 ft.) is only 1,700 feet taller than this 27,300-foot cube. This is as far as we will go. Three trillion tons of pennies is quite enough. To imagine larger cubes, (stepping by factors of 1,000), just imagine cubes roughly ten times larger than the last one. For instance, one quintillion pennies makes the cube above - about 5 miles on each side. If you step up to one sextillion, imagine a cube about 50 miles wide tall and thick.